ABSTRACT

A profound consideration of soil organic carbon (SOC) and SOC pools as affected by the long-term use of fertilizer in a fixed crop sequence is essential to understand and maintain the health and productivity of soil. The dynamics of SOC pools, i.e. total soil organic carbon (TOC) and its different fractions under a rice-wheat cropping system subjected to various fertilizer management strategies over 42 years was investigated near Uttarakhand, India. The soil at the experimental site was an Aquic Hapludoll consisting of a poorly drained silty clay loam (1–1.5 m deep) overlying loamy to sandy sediments. Over 42 years, application of 100% NPK+ FYM (Farm Yard Manure) was the most effective management system in increasing organic C up to 0 to 60 cm soil depths under rice-wheat sequence. The combination of this integrated input application (100% NPK + 15 t ha⁻¹ FYM) significantly built organic carbon fractions like total organic carbon, microbial biomass C (MBC), particulate organic C (POC), KMnO4 oxidizable C, Humic C, Fulvic C, Humin C, water-soluble carbon and hot water extractable carbohydrates at all four soil depths. Hence, application of FYM along with NPK resulted in a significant positive building up of all pools in the treatment at all four depths. Therefore, balance fertilization is panaceally important for sustaining improved soil health with balanced organic status and production potentiality of the soil for rice-wheat cropping sequence.

摘要

对土壤有机碳（SOC）和SOC池的深刻考虑是受固定作物序列中长期使用肥料的影响，对于理解和维护土壤的健康和生产力至关重要。SOC池的动态，即。在印度北阿坎德邦附近，调查了42年间经历了各种肥料管理策略的水稻-小麦种植系统下的土壤总有机碳（TOC）及其不同组分。实验地点的土壤是Aquic Hapludoll，由排水不畅的粉质粘土壤土（深1–1.5 m）组成，覆盖在壤土至沙质沉积物上。在42年的时间里，施用100％NPK + FYM（农家肥）是在稻麦顺序下将有机碳增加至0至60 cm土壤深度最有效的管理系统。该集成输入应用程序的组合（100％NPK + 15 t ha ^-1FYM）显着建立了有机碳馏分，例如总有机碳，微生物生物量C（MBC），颗粒有机C（POC），KMnO4可氧化C，腐殖酸C，腐霉菌C，Humin C，水溶性碳和可热水提取的碳水化合物四个土壤深度。因此，将FYM与NPK结合使用会在所有四个深度的处理中显着增加所有池的积极积聚。因此，平衡施肥对于维持改善的土壤健康，平衡有机状态和水稻-小麦种植顺序的土壤生产潜力至关重要。